This invention concerns farming, and in particular is directed to irrigation management on farms, especially including flood irrigation.
Irrigation of a farm field by flood irrigation, typically on a relatively flat field with a slight downward grade, is common in some geographical areas. For example, many crops are irrigated by flood irrigation in the Central Valley of California. In most recent years, water has been in short supply.
For such irrigation, water stored behind dams and directed through irrigation channels or pipes is applied by releasing the water at the higher end of a field and allowing that water to flow by gravity over all areas of the field. The field may be as small as about one-half acre or it could be many acres. Typically the field will have one crop, the water needs of which should be consistent in all areas. However, variations occur in surface contour, soil type and subsurface geology and, for example, some areas will drain water more quickly, with others holding water longer on the surface.
An objective of the invention is to maximize efficiency of water use in management of flood irrigation and other forms of irrigation on farms. In flood irrigation this involves sensing the presence of surface water at a series of different positions in a field, letting the farmer know when water reaches a particular area of the field and, optionally, how long the water remains. Also, related objectives are to measure soil moisture at various points and to determine water surface levels, including upstream and downstream of a gate, all to provide the farmer with complete and thorough information regarding an irrigation system to enable the farmer to manage irrigation more precisely and efficiently, saving water and time.
The following patents and applications may have some relevance to the invention: U.S. Pub. Nos. 2017/0127622, 2016/0219805, 2016/0183484, 2014/0361887, 2014/0225747; U.S. Pat. Nos. 8,739,830, 8,643,495, 8,326,440; China Pub. Nos. CN 105123446, CN 104542197 and CN 103210819.